This invention relates to video game apparatus. Specifically, apparatus is described for producing game markers displayed on a color television receiver.
Apparatus for supplying signals to a television receiver for displaying markers which may be manipulated to play simulated games of ping pong, tennis, or hockey are well known in the art and described in U.S. Pat. No. 3,659,285 by Rusch, Harrison, and Baer, and U.S. Pat. No. 3,659,284 by Rusch, hereby incorporated by reference. The game markers simulate player positions and game objects, and the players have player operable controls for moving the player position markers so as to intercept a game marker.
The apparatus described by these references provide a means for generating a luminance signal containing position and geometry information for each game marker to be displayed. The luminance signal of each game marker is combined with a vertical and horizontal sync signal. The resulting signal is used to modulate an R. F. signal in the receiver passband, and the modulated signal is applied to the antenna terminals of a standard television receiver. The television receiver when tuned to the R. F. signal frequency will display the game markers.
The references also describe a means for providing color to the game markers displayed on the television receiver. Color information is supplied by a chroma signal derived by pulsing a 3.579545 MHz signal according to the format of a game marker luminance signal. The phase of the resulting pulses of 3.579545 MHz signal is compared to the phase of a reference "burst" signal supplied by the video game with synchronous detectors in the television receiver. The video game produces the burst signal by pulsing the 3.579545 MHz signal with a delayed horizontal sync pulse.
The chroma signal produced by the video game apparatus is added to the luminance signals and sync signals, and the resulting composite signal is used to modulate the R. F. signal. By adding the chroma signal to the luminance signal, some problems of registration are produced when the delay experienced by chroma and luminance signals are not identical. Therefore, it is desirable to produce these signals simultaneously rather than combining separately produced luminance and chroma signals.